The present invention disclosed herein relates to a biochip and an apparatus for detecting a biomaterial using the biochip, and more particularly, to a biochip capable of enhancing the strength of a fluorescence signal emitted from a fluorophore upon specific binding of the biomaterial, and an apparatus for detecting a biomaterial using the biochip.
An apparatus for detecting a biomaterial (or a biosensor) is used to detect an optical or electrical signal varied with a selective reaction or binding between a biological receptor having the function of recognizing a specific biomaterial and an analyte to be analyzed. That is, the biosensor can confirm the presence of the specific biomaterial, or analyze the specific biomaterial quantitively or qualitively. Here, nucleic acid, protein, cell, tissue, enzyme, antibody and DNA may be used as the biological receptor (e.g., a capture molecule). There are various physical and chemical methods to detect and analyze biomaterials using an electrical signal change according to the presence of the analyte and an optical signal change according to the chemical reaction between the receptor and the analyte.
For an optical biosensor using the change of the optical signal, there is a labeling detection method for detecting a specific antigen quantitively. The labeling detection method uses the change of fluorescence signal strength or radioactive ray generated by a reaction between a labeled antigen and a specific antibody after labeling the specific antibody or antigen with a fluorophore or a radioactive isotope, respectively.
An optical sensor (e.g., fluorescence microscope) for detecting an optical signal from a biomaterial uses fluorescence emitted from a fluorophore to detect and analyze the biomaterial when an incident light having the same wavelength as the absorption wavelength of the fluorophore labeled on antibody or antigen is projected on a sample including the biomaterial. In this case, the fluorophore absorbs a light of a specific wavelength from an external light source, and emits a light of a specific wavelength according to the physical and chemical characteristics.
In the biosensor using the fluorophore, the fluorescence signal is not only emitted from the fluorophore according to the specific reaction of the antigen, but also voluntarily generated from the chip itself, i.e., a plastic material included in the chip. Accordingly, when the fluorescence signal is detected in the analysis of the biomaterial, the voluntary fluorescent signal emitted from the plastic material may act as an obstacle, i.e., a noise.
Also, the fluorescence signal may be generated from the fluorophore not only upon specific reaction between the antigen and the antibody, but also upon nonspecific reaction of the detection antibody labeled with the fluorophore. The fluorescence signal generated from the nonspecific reaction may also act as the noise in the biomaterial analysis.